Ventricular Lipoma Detection by Magnetic Resonance Imaging

During a routine physical examination, a 37-year-old womanwas noted to have a heart murmur. Her physician ordered a transthoracic echocardiogram for the presumptive diagnosis of mitral valve prolapse. Instead, the study showed a mass in the anterior wall of the left ventricle (Figure 1), with a question of a second mass involving the posterior papillary muscle. A trans-esophageal echocardiogram was performed, which again showed an anterior wall mass (Figure 2). The patient was scheduled for surgery to resect the mass; however, she requested a second opinion. A cardiac catheterization was performed, demonstrating normal right and left heart filling pressures, normal ventricular function, no significant coronary artery dis-ease, and no abnormal neovascularization in the left ventricular chamber. A MRI was ordered for further evaluation. Cardiac MRI showed a solitary, sharply marginated, bi-lobed mass arising from the endocardial surface of the left ventricle (Figure 3). No other masses were present. Regional wall motion near the mass was normal. The signal intensity of the mass was consistent with fat on several pulse sequences (Figures 3 and 4). First-pass perfusion imaging with MRI showed the mass was poorly perfused relative to normal myocardium (Figure 5). The MRI findings were diagnostic of a benign lipoma. The patient elected not to undergo surgical resection of the mass. A follow-up MRI 10 months later showed the mass was unchanged in size and shape (Figure 6). Cardiac lipomas are benign tumors of encapsulated mature adipose cells. They are frequently subendocardial in location and account for ’11 % of all cardiac neoplasms.1 MR signal characteristics of fat are quite specific, and they enabled cardiac MRI to be diagnostic in this case